tech.sirwellington.alchemy.kotlin.extensions.ThrowablesPlus.kt Maven / Gradle / Ivy

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/*
 * Copyright © 2019. Sir Wellington.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 *
 * You may obtain a copy of the License at
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package tech.sirwellington.alchemy.kotlin.extensions


/**
 * Returns the result in [block], or if an [Exception] is thrown,
 * returns `null` instead.
 *
 * @author SirWellington
 */
inline fun  tryOrNull(block: () -> (T)): T?
{
    return try
    {
        block()
    }
    catch (ex: Exception)
    {
        null
    }
}

/**
 * A more fine-grained version of [tryOrNull] that allows you to specify
 * a specific exception type that should be caught and treated as expected.
 *
 * If any other exception type is thrown, then it rethrown.
 *
 * > NOTE: Polymorphism applies.
 */
inline fun  tryOrNull(exceptionType: Class = E::class.java, block: () -> T): T?
{
    return try
    {
        block()
    }
    catch (ex: Throwable)
    {
        if (ex is E)
        {
            null
        }
        else
        {
            throw ex
        }
    }
}